That is one of those Great Debates. If your spare disk is a "hot spare" where it is plugged in and powered up, yes. If your spare disk philosophy is "cold spa

That is one of those Great Debates. If your spare disk is a "hot spare" where it is plugged in and powered up, yes. If your spare disk philosophy is "cold spare" where the drive is in a box on a shelf, probably not. Hot spares are faster and easier to turn into replacement drives but the "hot spare" is subject to usage-based (electrical, thermal, and mechanical) failure modes. For a given drive, the probability of failure is largely proportional to power-on hours[1]. Cold spares are not accumulating power-on hours so they likely won't fail while waiting to be used and presumably won't fail for quite some time after being installed as a replacement. [1] Intuitively, but hard to prove because of many confounding factors. Backblaze has the best drive failure rate data that I'm aware of: https://www.backblaze.com/b2/hard-drive-test-data.html https://www.backblaze.com/b2/hard-drive-test-data.html